LINQ is not an ORM. There is LINQ to Objects and LINQ to XML, which query collections and XML documents respectively.
The first ORM over Linq from Microsoft was Linq to SQL. This is now deprecated, and the second one is called Entity Framework (EF), which was a more ambitious but slower-moving project. In the latest release, EF 4.1, it's actually quite good.
NHibernate is still very popular, in part because over the confusion over Linq to SQL and EF, in part becuase it was there first and is very mature.
There are a whole lot of other, less-well-known .Net ORMS - SubSonic, SimpleData ... just google ".net orm". But for new work, most people would only consider EF and NHibernate.
LINQ is not an ORM. There is LINQ to Objects and LINQ to XML, which query collections and XML documents respectively.
The first ORM over Linq from Microsoft was Linq to SQL. This is now deprecated, and the second one is called Entity Framework (EF), which was a more ambitious but slower-moving project. In the latest release, EF 4.1, it's actually quite good.
NHibernate is still very popular, in part because over the confusion over Linq to SQL and EF, in part becuase it was there first and is very mature.
There are a whole lot of other, less-well-known .Net ORMS - SubSonic, SimpleData ... just google ".net orm". But for new work, most people would only consider EF and NHibernate.
There's even a Linq to NHibernate:http://ayende.com/blog/4083/nhibernate-linq-1-0-released
That and fluent NHibernate take some of the pain out of configuring NHibernate.